Withers R T, Hamdorf P A
Exercise Physiology Laboratory, School of Education, Flinders University of South Australia, Bedford Park.
J Sports Sci. 1989 Spring;7(1):21-30. doi: 10.1080/02640418908729819.
Immersion of 18 male subjects in water caused a 20.4% (787 ml) increase (P less than 0.05) in the mean inspiratory capacity (IC) whereas there were no changes (P greater than 0.05) in tidal volume (VT) and the frequency of respiration. All the means for the other pulmonary variables decreased (P less than 0.05) by varying amounts: total lung capacity (TLC) = 8.4% (599 ml), vital capacity (VC) = 5.5% (308 ml), functional residual capacity (FRC) = 42.6% (1386 ml), expiratory reserve volume (ERV) = 61.9% (1095 ml) and residual volume (RV) = 19.7% (292 ml). Variation of only the RV in the body density (BD) formula from which the percentage body fat (%BF) is estimated resulted in a significantly (P less than 0.05) lower mean of 15.2% BF for the RV in air (means = 1482 ml) compared with that of 17.1% BF for the RV in water (means = 1190 ml). All but one of the subjects exhibited a smaller RV in water than in air; the six largest differences were equivalent to 2.4-5.1% BF. These results indicate that the net effect of the hydrostatic pressure (decreases RV), pulmonary vascular engorgement (decreases RV) and diminished compliance (increases RV) is to reduce the ventilated RV. It is therefore advisable to measure the RV when the subject is immersed in order to minimize error in the determination of BD and hence the estimation of % BF.
将18名男性受试者浸入水中后，平均吸气量（IC）增加了20.4%（787毫升）（P<0.05），而潮气量（VT）和呼吸频率没有变化（P>0.05）。其他肺功能变量的所有平均值均有不同程度下降（P<0.05）：肺总量（TLC）=8.4%（599毫升），肺活量（VC）=5.5%（308毫升），功能残气量（FRC）=42.6%（1386毫升），补呼气量（ERV）=61.9%（1095毫升），残气量（RV）=19.7%（292毫升）。用于估算体脂百分比（%BF）的身体密度（BD）公式中，仅RV的变化就导致与水中RV的平均17.1%BF相比，空气中RV的平均15.2%BF显著降低（P<0.05）（平均值分别为1482毫升和1190毫升）。除一名受试者外，所有受试者在水中的RV均小于在空气中的RV；最大的六个差异相当于2.4 - 5.1%BF。这些结果表明，静水压力（降低RV）、肺血管充血（降低RV）和顺应性降低（增加RV）的综合作用是减少通气的RV。因此，建议在受试者浸入水中时测量RV，以尽量减少BD测定中的误差，从而减少%BF估算中的误差。
